1. Field of the Invention
This invention relates generally to body treatment care and specifically to garments used in emergency treatment of victims suffering from hypovolemic shock and in the presence of intractable bleeding.
2. Description of the Prior Art
Shock is a life threatening condition that results when the body is unable to maintain circulation to the heart, lungs and brain. It may be caused by trauma, blood loss, toxins or other circulatory diminishment. In addition to the routine shock first-aid of lying the victim prone with the lower extremities raised to move blood to the critical organs, it is also known to apply surface counterpressure to the lower extremities sufficient to overcome the pressure in the capillary and venus system to force increased circulation to the critical organs.
Circumferential pneumatic counterpressure (CPC) devices are well known inflatable garments used to apply pressure around the arms, legs and/or abdomen to control intractable bleeding and ameliorate shock. Examples of such devices are described in U.S. Pat. No. 3,933,150 issued Jan. 20, 1976, to Kaplan et al., and U.S. Pat. No. 4,039,039 issued Aug. 2, 1977, to Gottfried. The application of a CPC device causes a dramatic circulatory rearrangement of the blood within a victim's body. The victim's blood pressure rises and the volume of blood available to the heart, lungs and head is greatly increased, while the amount of blood in the lower extremities is decreased.
The safety of CPC devices has been questioned because of the ease in which one can overpressurize the garment and cause restriction of the respiratory process, acidosis or ischemic injury (where the garment presses the skin against underlying bone). A standard method of pressure in a CPC is by using a foot-pump, which makes it extremely difficult to maintain a constant pressure for any length of time. Also, the conditions and excitement surrounding an emergency situation, often result in the ambulance crew over-inflating the garment.
Another problem associated with CPC garments is the rapid pressure drop from the accidental puncturing of one or more bladders. A rapid depressurization could be fatal since the victim's blood pressure can decrease by as much as 60 mm Hg.
Pressurized garments are susceptible to temperature and atmospheric pressure changes, forcing the ambulance crew to constantly adjust the garment's pressure. For example, if a skier at the top of a mountain is involved in an accident and is placed in a CPC garment, the pressure within the garment's bladders will change when the skier is brought down to ground level and indoor temperature.
Since the pneumatic pressure fittings are usually metallic, a victim normally cannot be X-rayed for possible fractures while in the garment. Further, the garment usually Cannot be cut away in selected areas to expose portions of the victims body for treatment, as the cutting would open an air bladder and cause depressurization.